netfilter-devel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Patrick McHardy <kaber@trash.net>
To: Philip Craig <philipc@snapgear.com>
Cc: Thomas Jarosch <thomas.jarosch@intra2net.com>,
	Jan Engelhardt <jengelh@medozas.de>,
	hadi@cyberus.ca, Pablo Neira Ayuso <pablo@netfilter.org>,
	netfilter-devel@vger.kernel.org
Subject: Re: [PATCH] libxtables: Dont initialize global xt_params
Date: Mon, 16 Feb 2009 11:38:49 +0100	[thread overview]
Message-ID: <49994239.6000307@trash.net> (raw)
In-Reply-To: <4998F0EE.3020404@snapgear.com>

Philip Craig wrote:
> Thomas Jarosch wrote:
>> Well, I guess that's a job for the compiler/optimizer. I did a quick test by 
>> writing two versions of a small program initializing a static variable with 
>> zero and one version that doesn't (=zeroed in .bss). Guess what,
>> the size of the resulting executable stays the same.
>>
>> When I initialize the variable with a non-zero value, then the program size 
>> increases. I tested "-O2", "-O0" and "-Os" and the results where the same.
>> Feel free to look at the assembler output, though I guess this optimization
>> is not measurable and makes the code harder to read :o)
> 
> For gcc, this depends on the -fno-zero-initialized-in-bss option.
> Recommendations to avoid zero initialization generally come from
> a time when gcc didn't do this by default.  Now it is more just
> personal preference.

I think the 3.x versions don't do this by default, so as long as they're
supported by the kernel, we should expect people to use them and not
assume defaults of later versions.

  reply	other threads:[~2009-02-16 10:38 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-02-12 14:16 [PATCH] libxtables: Dont initialize global xt_params jamal
2009-02-12 15:09 ` Thomas Jarosch
2009-02-12 15:14   ` Jan Engelhardt
2009-02-12 15:41     ` Thomas Jarosch
2009-02-13 13:49       ` jamal
2009-02-13 18:11         ` Thomas Jarosch
2009-02-16  4:51       ` Philip Craig
2009-02-16 10:38         ` Patrick McHardy [this message]
2009-02-17 14:46           ` Thomas Jarosch
2009-02-17 14:54             ` Patrick McHardy
2009-02-12 16:39 ` jamal

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=49994239.6000307@trash.net \
    --to=kaber@trash.net \
    --cc=hadi@cyberus.ca \
    --cc=jengelh@medozas.de \
    --cc=netfilter-devel@vger.kernel.org \
    --cc=pablo@netfilter.org \
    --cc=philipc@snapgear.com \
    --cc=thomas.jarosch@intra2net.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).